Most of the people in the room when the United States gave its sole presentation last week at COP23 — the United Nations climate negotiations in Bonn, Germany — were protesters. Around the 20-minute mark, 100 people — mostly Americans — stood up, sang an altered version of “God Bless the U.S.A.,” turned their backs to the panel of White House officials and fossil fuel industry representatives, and walked out. The event then continued before a room filled mainly with...